In recent studies, however, when taking into account the presence of eosinophils, local production of IgE by plasma cells, increase in mastocytes number, detection of B and T cells, and participation of IL-2, an updated model suggests that the pathophysiology of AP is based on a type IV hypersensitivity reaction- specifically, subtype b-although subtype a can not be dismissed completely, based on these findings (16,24,36,39-41). This evidence concerns the gene IGHE and alkaline phosphatase measurement.